LOLZ97

if instance_position(x,y-8,oWalkEnemy) {
vspd=-10
with instance_position(x,y-8,oWalkEnemy) dead=true
}
else{
if instance_position(x,y,oWalkEnemy)
dead=true
}

Right now, you the enemy only dies if you are below it. I'd guess this is not the behavior you want.

IDK whats hard to understand,

dllinit(false,true,true) to initialize.
dllend() to end
clearbuffer() to clear the buffer
sendmessage(socket) sends a message
receivemessage(socket) receives a message
writebyte(), writeushort(), writeshort() with there respective arguments are saved in the buffer till there sent.

Whats the part you don't understand?

There are a bunch of tutorials just for this in the tutorials section to help get you started.
If you actually are using 39dll, in the zip file that comes with it are actual tutorials 39ster made that you can look at.

I recommend Faucet Networking, personally.